I’m writing a CMS application in PHP and one of the requirements is that it must be able to interface with the customer’s Exchange server. I’ve written up this functionality a few times before and have always used WebDAV to do it, but now I’m leaning away from that. I will be running the site on IIS OR Apache (no preference) on Windows server 2008. A few things I would need to do include adding contacts to a given user’s address book, sending emails as a given user and running reports on contacts for a user. All of this is pretty easy to do with WebDAV, but if there is a better way that doesn’t require any functionality that is likely to be deprecated any time soon. Any ideas?